/*
 * $Id: StackLayout.java 3793 2010-09-28 05:15:02Z kschaefe $
 *
 * Copyright 2005 Sun Microsystems, Inc., 4150 Network Circle,
 * Santa Clara, California 95054, U.S.A. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
package org.jdesktop.swingx;

import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Insets;
import java.awt.LayoutManager2;
import java.awt.Rectangle;
import java.util.LinkedList;
import java.util.List;

/**
 * <p>
 * <code>StackLayout</code> is a Swing layout aimed to act as the layers stack
 * of most popuplar graphics editing tools like <i>The GIMP</i> or
 * <i>Photoshop</i>. While similar to <code>CardLayout</code>, this layout
 * displays all the components of the container. If you are using
 * non-rectangular components (i.e. transparent) you will see them from top to
 * bottom of the stack.
 * </p>
 * <p>
 * When using this layout, each component can be added in the container either
 * on top of the stack or at the bottom:
 * </p>
 * 
 * <pre>
 * JPanel panel = new JPanel(new StackLayout());
 * panel.add(new JLabel(&quot;On top&quot;), StackLayout.TOP);
 * panel.add(new JLabel(&quot;At bottom&quot;), StackLayout.BOTTOM);
 * </pre>
 * 
 * If you don't specify the constraint, the component will be added at the top
 * of the components stack.</p>
 * <p>
 * All the components managed by this layout will be given the same size as the
 * container itself. The minimum, maximum and preferred size of the container
 * are based upon the largest minimum, maximum and preferred size of the
 * children components.
 * </p>
 * <p>
 * <code>StackLayout</code> works only with JSE 1.5 and Java SE 6 and greater.
 * </p>
 * 
 * @author Romain Guy <romain.guy@mac.com>
 */

public class StackLayout implements LayoutManager2 {
	/** Use this constraint to add a component at the bottom of the stack. */
	public static final String BOTTOM = "bottom";
	/** Use this contrainst to add a component at the top of the stack. */
	public static final String TOP = "top";

	// removing components does not happen often compared to adding components
	// hence we choose a linked list to make insertion at the bottom faster
	private List<Component> components = new LinkedList<Component>();

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void addLayoutComponent(final Component comp, final Object constraints) {
		synchronized (comp.getTreeLock()) {
			if (BOTTOM.equals(constraints)) {
				components.add(0, comp);
			} else if (TOP.equals(constraints)) {
				components.add(comp);
			} else {
				components.add(comp);
			}
		}
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void addLayoutComponent(final String name, final Component comp) {
		addLayoutComponent(comp, TOP);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void removeLayoutComponent(final Component comp) {
		synchronized (comp.getTreeLock()) {
			components.remove(comp);
		}
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public float getLayoutAlignmentX(final Container target) {
		return 0.5f;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public float getLayoutAlignmentY(final Container target) {
		return 0.5f;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void invalidateLayout(final Container target) {
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public Dimension preferredLayoutSize(final Container parent) {
		synchronized (parent.getTreeLock()) {
			int width = 0;
			int height = 0;

			for (Component comp : components) {
				Dimension size = comp.getPreferredSize();
				width = Math.max(size.width, width);
				height = Math.max(size.height, height);
			}

			Insets insets = parent.getInsets();
			width += insets.left + insets.right;
			height += insets.top + insets.bottom;

			return new Dimension(width, height);
		}
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public Dimension minimumLayoutSize(final Container parent) {
		synchronized (parent.getTreeLock()) {
			int width = 0;
			int height = 0;

			for (Component comp : components) {
				Dimension size = comp.getMinimumSize();
				width = Math.max(size.width, width);
				height = Math.max(size.height, height);
			}

			Insets insets = parent.getInsets();
			width += insets.left + insets.right;
			height += insets.top + insets.bottom;

			return new Dimension(width, height);
		}
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public Dimension maximumLayoutSize(final Container target) {
		return new Dimension(Integer.MAX_VALUE, Integer.MAX_VALUE);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void layoutContainer(final Container parent) {
		synchronized (parent.getTreeLock()) {
			int width = parent.getWidth();
			int height = parent.getHeight();

			Rectangle bounds = new Rectangle(0, 0, width, height);

			int componentsCount = components.size();

			for (int i = 0; i < componentsCount; i++) {
				Component comp = components.get(i);
				comp.setBounds(bounds);
				parent.setComponentZOrder(comp, componentsCount - i - 1);
			}
		}
	}
}
